Our expert Gastroenterologists make getting care easy

John E. Carroll, MD

John E. Carroll, MD, is a Gastroenterologist at MedStar Georgetown University Hospital. Board certified in Internal Medicine and Gastroenterology, Dr. Carroll has been at Georgetown for twenty seven years. After graduating from medical school in Wisconsin, Dr. Carroll came to Georgetown for his internship in 1993, where he stayed and completed all of his postgraduate and specialty training. Dr. Carroll grew up in Chicago, and earned his degree in biomedical engineering at Marquette University.

Dr. Carroll did advanced training in endoscopic ultrasound (EUS) at Georgetown, and has been specializing in performing EUS procedures of the GI tract for 20 years. In addition to his interest in EUS procedures of the pancreas, stomach and biliary systems, Dr. Carroll also has extensive interest and expertise in treating disorders of the esophagus, such as Barrett’s esophagus and early invasive esophageal cancers. With the increasing advances in endoscopic technology which have developed in recent years, Dr. Carroll and his colleagues are routinely successfully curing early esophageal cancers endoscopically, which up until recently had required large surgeries to cure.

During his spare time Dr. Carroll enjoys skiing, sailing, travel, and following D.C. sports, in particular the Washington Nationals.

Walid Chalhoub, MD

After completing fellowships in both gastroenterology and advanced gastroenterology (ERCP/EUS) at MedStar Georgetown University Hospital, Walid M. Chalhoub, MD, joined the hospital's medical staff in 2016 as an assistant professor of Medicine in the Department of Gastroenterology affiliated with the Georgetown University School of Medicine. Previously, Dr. Chalhoub was an attending physician in general medicine at Memorial Sloan Kettering Cancer Center and an instructor at Weill Medical College of Cornell University in New York City.

Upon graduating from medical school, Dr. Chalhoub first worked for several years as a clinical researcher and coordinator at the Mount Sinai Medical Center. He then completed his internship and residency at the medical center's Elmhurst Program, where he was appointed chief resident followed by an appointment to the medical staff as a general medicine attending physician.

Dr. Chalhoub has a special interest in diagnosing and treating pancreatic and biliary disease with advanced endoscopic techniques. An accomplished researcher, his work has been published in peer-reviewed journals and textbooks, and presented at national conferences including the American College of Gastroenterology Annual Meeting and Digestive Disease Week.

Philosophy of Care:
My emphasis first and foremost is the quality of care. I treat a patient as a whole. Patients in general are all going through stressful and hard times physically, mentally, and emotionally. We are here to make sure their medical journey feels understood, supported, and treated with the utmost expertise, clarity, dignity, and respect.

Nadim Haddad, MD

Nadim Haddad, MD, is board certified in internal medicine and gastroenterology. Dr. Haddad serves as physician executive director and regional chief of the Department of Gastroenterology services at MedStar Georgetown University Hospital. He sees adult patients for conditions affecting the gastrointestinal tract, such as pancreatic and bilary diseases, with a focus on cancer. In addition to adults, Dr. Haddad also attends to pediatric patients for upper gastrointestinal endoscopy.

Dr. Haddad's approach to care focuses on getting to know his patients treating the person, not a disease. His emphasizes hope when patients are facing a serious condition, such a cancer.

Dr. Haddad is also involved in research, focusing in the areas of pancreatic cancer and pancreatic cysts. He was instrumental in developing a pancreatic cyst registry that allows multiple academic medical centers and universities to collaborate and look at the role of molecular profiling.

In addition, Dr. Haddad is active in training the next generation of physicians as an associate professor at Georgetown University. As director of the Gastroenterology Fellowship Program, he was instrumental in it gaining full accreditation.

In his free time, Dr. Haddad is active in the Washington community, involved in his children's schools and with his church.

Joseph J. Jennings, MD

Joseph J. Jennings, MD is a board-certified gastroenterologist with a focus on bleeding within the GI tract. Dr. Jennings graduated from Georgetown University School of Medicine in 2012 and completed his Internal Medicine training at MedStar Georgetown University Hospital in 2015. He served as the Chief Medical Resident for MedStar Georgetown University Hospital and served as an attending physician in Internal Medicine at the Washington DC VA Medical Center and Virginia Hospital Center as well. He completed his three year fellowship in Gastroenterology at MedStar Georgetown University Hospital and served as Chief Fellow in 2018-2019.

Dr. Jennings strives to create a relationship with his patients that promotes joint decision making and patient empowerment. He also has a strong interest in medical education and training. He currently serves as the associate director for the MedStar Georgetown University Hospital's gastroenterology fellowship program.

Dr. Jennings is board certified in Internal Medicine since 2015 and Gastroenterology/Hepatology since 2019.

Priyanka Kanth, MD

Priyanka Kanth, MD, is a gastroenterologist at MedStar Georgetown University Hospital. Fellowship-trained and board-certified in gastroenterology, Dr. Kanth leads the Gastrointestinal Cancer Prevention Program for patients and families with high risk for gastrointestinal cancers. Her area of special interest and expertise is gastrointestinal cancer, especially hereditary colon cancer and colon cancer prevention.

She graduated from medical school and completed her internship at Kasturba Medical College, Mangalore, MAHE University, India. She completed a residency in internal medicine at University of Connecticut Health, Farmington, CT, where she was Chief Medical Resident, and a residency in colorectal and general surgery at Royal Albert Edward Infirmary in the United Kingdom, as well as a fellowship in gastroenterology at University of Utah Health in Salt Lake City.

Dr. Kanth’s areas of clinical expertise include colon polyps, serrated colon polyps, hereditary gastrointestinal cancer syndromes, including Lynch syndrome, familial adenomatous polyposis, juvenile polyposis syndrome, Peutz-Jeghers syndrome, serrated polyposis syndrome, hamartomatous polyposis syndromes, hereditary diffuse gastric cancer, gastrointestinal cancer genetics, and the prevention of colon cancer.

She has served as principal investigator and site principal investigator for several studies on issues related to gastrointestinal cancer. Her research has been published in several peer-reviewed journals, including NEJM, JAMA, Genetic Epidemiology, Gut, Gastroenterology, Clinical and Translational Gastroenterology, and Journal of National Comprehensive Cancer Network. She also has presented at numerous national and international conferences.

Dr. Kanth believes in educating her patients, so they are aware of their personal and family history of gastrointestinal and other cancers. This knowledge is important, because many of these cancers can be prevented and detected early, especially in the case of genetic conditions that increases cancer risk. She is a firm believer in listening to her patients, answering all their questions, and coming to a mutual decision about their care.

In her spare time, she enjoys movies, traveling, and spending time with family.

James Lewis, MD

Board-certified in gastroenterology and internal medicine, James H. Lewis, MD, has spent more than 30 years treating all forms of chronic and acute liver disease as a sub-specialty in the Washington, D.C., area. Dr. Lewis is Professor of Medicine at Georgetown University School of Medicine, and Director of Hepatology in the Division of Gastroenterology. He currently serves as Associate Director of the Gastroenterology Fellowship training program of the combined MedStar Georgetown University Hospital, MedStar Washington Hospital Center and the DC Veteran's Affairs Medical Center.

A recognized local and national expert on the management of hepatitis B, hepatitis C and drug induced liver disease, Dr. Lewis is widely published in the profession's most prestigious clinical journals. He also serves as a reviewer for multiple journals and on editorial boards. The author of several books and numerous book chapters, Dr. Lewis is a frequent lecturer at the regional and national level.

In addition to direct patient care, Dr. Lewis has extensive consulting experience with the FDA and pharmaceutical manufacturers on a variety of liver-related conditions. His special research interests include viral hepatitis and drug induced liver injury. Dr. Lewis is committed to his patients and often cares for those dealing with very complex liver conditions, including acute liver failure, cirrhosis, and people who have failed prior treatment for hepatitis B and C.

Thomas M. Loughney, MD

Board-certified in Gastroenterology, Thomas Loughney, MD, currently serves as Director of Endoscopy at MedStar Georgetown University Hospital and is an Associate Professor, Georgetown Medical School. He is the Chairman of the Credentials Committee. He also serves on the MedStar Georgetown Patient Safety Committee.

Dr. Loughney has won multiple awards for his excellence in teaching and been recognized by Washington's Consumer Checkbook and Washingtonian Magazine as the top, recommended gastroenterologist in the Washington area. His clinical expertise includes interventional endoscopy, biliary and pancreatic disease, use of endoluminal stents and colon cancer screening.

Following a Gastroenterology Fellowship and Residency and Internship in Internal Medicine all at Walter Reed National Military Medical Center Dr. Loughney served as a Lt. Colonel in the Army Medical Corp. He graduated from Georgetown University School of Medicine in 1989.

Mark Mattar, MD

Dr. Mattar is the director of the IBD Center, with expertise in diagnosing and treating inflammatory bowel diseases (IBD), Crohn's disease, colitis, and celiac disease. Dr. Mattar has a particular interest in IBD therapeutics and IBD and colorectal cancer prevention. He is active in clinical research and medical education for trainees, the community, and patients.

Dr. Mattar sees patients in his gastroenterology practice at MedStar Georgetown University Hospital. He embraces a team approach to patient care within the IBD Center at MedStar Georgetown as part of a multidisciplinary treatment team that includes dietitians and other key providers. He is also active in clinical trials for IBD and performs fecal microbiota transplantation for recurrent and refractory C. difficile infection.

Dr. Mattar teaches at MedStar Georgetown University Hospital as Associate Professor of Medicine, and is the director of the Fellowship Training Program in Gastroenterology. He is also an active member of the Crohn's and Colitis Foundation D.C. Metro chapter mission committee, the Professional Education National Scientific Advisory Committee and the Northeast Regional MyIBD Learning Planning Committee.

As the Quality Improvement Officer for the Division of Gastroenterology, Dr. Mattar has been recognized by the American Gastroenterological Association's Bridges to Excellence Program for his commitment to providing comprehensive quality care for patients with IBD.

Dr. Mattar enjoys family time with his wife and son, including fishing in local ponds and creeks. He especially enjoys exploring the Washington museums and playgrounds with his young son. He also enjoys checking out the local cafes and creating his own latte art.

Patients and practitioners can connect with Dr. Mattar on Twitter ( @gastrodocmattar) and follow his tweets on new developments in gastroenterology.

The mission of the training program he directs states, "To create an environment where compassionate medical trainees can learn to provide exceptional quality care to the patients we serve." He prides himself in treated his patients as he would his own family.

Angelica Nocerino, MD

Angelica Nocerino, MD, is a gastroenterologist at MedStar Georgetown University Hospital. Fellowship-trained in gastroenterology, Dr. Nocerino is committed to providing patients living with conditions that affect the digestive tract with excellent care and leading-edge treatments.

After graduating from medical school at Georgetown University School of Medicine, she completed her internship, residency, and fellowship in gastroenterology at Northwell Health-Lenox Hill Hospital, New York, NY, where she served as chief resident in internal medicine and chief fellow in gastroenterology.

Dr. Nocerino’s areas of clinical expertise include neurogastroenterology and motility. She treats patients with the full range of conditions that affect the esophagus, stomach, small bowel, and colon and anorectum, including irritable bowel syndrome, achalasia, esophagogastric junction outflow obstruction, gastroesophageal reflux disease (GERD), gastroparesis, small intestinal bacterial overgrowth, intestinal dysmotility, chronic constipation, food hypersensitivity, and fecal incontinence.

Dr. Nocerino will be using Endoflip™ in her practice, a technology that measures esophageal motility, making MedStar Georgetown University Hospital one of the few centers in the area to offer this test. Dr. Nocerino will be offering esophageal high resolution manometry testing, wireless and catheter-based pH testing for acid reflux, anal rectal manometry for pelvic floor dysfunction, and SmartPill motility testing.

She has been published in several prestigious medical journals, including the American Journal of Gastroenterology, the Journal of Allergy and Infectious Diseases, Digestive Diseases and Sciences, and Practical Gastroenterology, and has presented at conferences. She is an active researcher and her current work is focused on the Smart Pill motility testing system and gastroparesis.

Dr. Nocerino believes in taking care of the whole person, carefully listening to every patient and reviewing their lifestyle and diet to help get to the root cause of their disease. For each patient, she individualizes treatments to improve wellness and quality of life.

In her spare time, she enjoys traveling, spending time with family and friends, cooking, and cycling.

Caren Palese, MD

Caren Palese, MD, is board certified in both Internal Medicine and Gastroenterology and is an Associate Professor of Internal Medicine and Gastroenterology at MedStar Georgetown University Hospital. She is board certified in both Internal Medicine and Gastroenterology and is an Associate Professor of Internal Medicine and Gastroenterology at MedStar Georgetown University Hospital. Dr. Palese completed her undergraduate studies at Princeton University and received her medical degree from the Icahn School of Medicine at Mount Sinai in New York City. She completed her internship and residency in Internal Medicine, followed by a three-year Gastroenterology fellowship at Georgetown University Medical Center.

Since 2014, she has been consistently chosen by her peers to be a Washingtonian Magazine’s Top Doc. She has been awarded the annual distinction of Castle Connolly Top Doctor since 2016. In addition, she has received the Castle Connolly Exceptional Women in Medicine Award. She was selected by the Washington Post Magazine to be a Rising Star in 2013.

Dr. Palese uses progressive techniques to diagnose and treat many esophageal disorders, such as GERD, eosinophilic esophagitis and Barrett’s esophagus. She is an expert in diseases of swallowing.

For the most effective care and optimal outcomes for her patients, Dr. Palese takes a multidisciplinary approach and often works closely with a team of specialists. In addition to her expertise in swallowing disorders, Barrett’s esophagus and gastrointestinal motility disorders, Dr. Palese performs precise screening colonoscopies for detecting colon cancer and flat polyps.

Beyond her passion for her work, Dr. Palese enjoys speaking German, running and skiing.

Stanley Pietrak III, MD

Stanley J. Pietrak, MD, is a board-certified gastroenterologist at MedStar Washington Hospital center. In addition to his dedication to general gastroenterology care, Dr. Pietrak diagnoses and treats both benign and malignant diseases of the bile ducts, pancreas, and the pancreatic ducts, with a focus on therapeutic endoscopy.

Dr. Pietrak utilizes endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic ultrasound (EUS) to provide minimally invasive treatment of the bile and pancreatic ducts. His clinical interests include malignant and benign disorders of the bile ducts, malignant and benign disorders of the pancreas, advanced polypectomy removal, staging of luminal gastrointestinal cancer, and endoscopic luminal stenting. His research interests include pancreatic cancer screening and endoscopy training proficiency for gastrointestinal fellows.

Dr. Pietrak received his medical degree from Albany Medical College, where he was elected to the Alpha Omega Alpha Medical Honor Society. He completed a three-year residency in internal medicine at MedStar Georgetown University Hospital. He then joined Drexel University College of Medicine for a three-year fellowship in gastroenterology, where he was Chief Fellow. Before joining MedStar Washington Hospital Center, Dr. Pietrak completed a specialty fellowship in advanced gastroenterology therapeutics with MedStar Georgetown University Hospital. He is a member of the American College of Gastroenterology (ACG), the American Gastroenterological Association (AGA), and the American Society for Gastrointestinal Endoscopy (ASGE).

Dr. Pietrak is passionate about the early detection and management of patients with pancreatic cysts.

Philosophy of Care:
“In order to maximize the quality and effectiveness of the care I provide, I strive to practice evidence-based medicine with a patient-centered focus. While we must acknowledge the recommendations of national guidelines and landmark clinical research trials, each patient presents us with a unique situation or condition. As a result, we must not only focus on treating their medical issues, but also their individual concerns and needs.”

Shervin Shafa, MD

Dr. Shafa completed a fellowships in Gastroenterology at MedStar Georgetown University Hospital followed and at the University of North Carolina at Chapel Hill. He is also trained in advanced therapeutics for malignant and benign lesions of the esophagus.

Dr. Shafa's research interests include endoscopic techniques and non-invasive methods for diagnosis and management of early esophageal cancer and Barrett's esophagus.

Dr. Shafa also performs cryoablative therapy for treatment of Barrett’s esophagus and esophageal cancers.